Feat: Add Homebrew Cask installation support

[ryan6416]

Description

Installing KeyType currently requires manual download, mounting the DMG, and dragging the binary. Adding a Homebrew Cask simplifies distribution and automates updates for macOS users.

Proposed Solution

Create a canonical Homebrew Cask definition. Since KeyType is a GUI menu-bar application built for macOS 14+, a Cask is the native, idiomatic delivery mechanism.

Here is the exact cask implementation (keytype.rb):

cask "keytype" do
  version "1.4"
  sha256 "ADD_V1.4_DMG_SHA256_HERE"

  url "[https://github.com/johnbean393/KeyType/releases/download/#](https://github.com/johnbean393/KeyType/releases/download/#){version}/KeyType.dmg"
  name "KeyType"
  desc "Open-source, on-device, system-wide tab-autocomplete utility"
  homepage "[https://github.com/johnbean393/KeyType](https://github.com/johnbean393/KeyType)"

  auto_updates true
  depends_on macos: ">= :sonoma"

  app "KeyType.app"

  uninstall quit: "com.johnbean393.KeyType"

  zap trash: [
    "~/Library/Application Support/KeyType",
    "~/Library/Preferences/com.johnbean393.KeyType.plist",
  ]

  caveats <<~EOS
    KeyType requires Accessibility permissions. 
    Enable it under System Settings > Privacy & Security > Accessibility.
  EOS
end

[johnbean393]

@ryan6416

Will do! Thanks for the suggestion.